diff --git a/docs/design/cpu-specific-build-macros.rst b/docs/design/cpu-specific-build-macros.rst
index 7fa027f..f3096b4 100644
--- a/docs/design/cpu-specific-build-macros.rst
+++ b/docs/design/cpu-specific-build-macros.rst
@@ -324,6 +324,11 @@
    as recommended in section "4.7 Non-Temporal Loads/Stores" of the
    `Cortex-A57 Software Optimization Guide`_.
 
+-  ``NEOVERSE_N1_EXTERNAL_LLC``: This flag indicates that an external last
+   level cache(LLC) is present in the system, and that the DataSource field
+   on the master CHI interface indicates when data is returned from the LLC.
+   This is used to control how the LL_CACHE* PMU events count.
+
 --------------
 
 *Copyright (c) 2014-2019, Arm Limited and Contributors. All rights reserved.*
diff --git a/include/lib/cpus/aarch64/neoverse_n1.h b/include/lib/cpus/aarch64/neoverse_n1.h
index fa733ce..b50befa 100644
--- a/include/lib/cpus/aarch64/neoverse_n1.h
+++ b/include/lib/cpus/aarch64/neoverse_n1.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2020, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -35,6 +35,7 @@
 
 #define NEOVERSE_N1_WS_THR_L2_MASK	(ULL(3) << 24)
 #define NEOVERSE_N1_CPUECTLR_EL1_MM_TLBPF_DIS_BIT	(ULL(1) << 51)
+#define NEOVERSE_N1_CPUECTLR_EL1_EXTLLC_BIT		(ULL(1) << 0)
 
 /*******************************************************************************
  * CPU Auxiliary Control register specific definitions.
diff --git a/lib/cpus/aarch64/neoverse_n1.S b/lib/cpus/aarch64/neoverse_n1.S
index d058d98..d537ed6 100644
--- a/lib/cpus/aarch64/neoverse_n1.S
+++ b/lib/cpus/aarch64/neoverse_n1.S
@@ -465,6 +465,13 @@
 	msr	CPUAMCNTENSET_EL0, x0
 #endif
 
+#if NEOVERSE_N1_EXTERNAL_LLC
+	/* Some system may have External LLC, core needs to be made aware */
+	mrs     x0, NEOVERSE_N1_CPUECTLR_EL1
+	orr     x0, x0, NEOVERSE_N1_CPUECTLR_EL1_EXTLLC_BIT
+	msr     NEOVERSE_N1_CPUECTLR_EL1, x0
+#endif
+
 #if ERRATA_DSU_936184
 	bl	errata_dsu_936184_wa
 #endif
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index 398edf9..e3bfc2f 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2014-2019, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2014-2020, ARM Limited and Contributors. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
@@ -20,6 +20,10 @@
 WORKAROUND_CVE_2018_3639	?=1
 DYNAMIC_WORKAROUND_CVE_2018_3639	?=0
 
+# Flag to indicate internal or external Last level cache
+# By default internal
+NEOVERSE_N1_EXTERNAL_LLC	?=0
+
 # Process SKIP_A57_L1_FLUSH_PWR_DWN flag
 $(eval $(call assert_boolean,SKIP_A57_L1_FLUSH_PWR_DWN))
 $(eval $(call add_define,SKIP_A57_L1_FLUSH_PWR_DWN))
@@ -43,6 +47,9 @@
 $(eval $(call assert_boolean,DYNAMIC_WORKAROUND_CVE_2018_3639))
 $(eval $(call add_define,DYNAMIC_WORKAROUND_CVE_2018_3639))
 
+$(eval $(call assert_boolean,NEOVERSE_N1_EXTERNAL_LLC))
+$(eval $(call add_define,NEOVERSE_N1_EXTERNAL_LLC))
+
 ifneq (${DYNAMIC_WORKAROUND_CVE_2018_3639},0)
     ifeq (${WORKAROUND_CVE_2018_3639},0)
         $(error "Error: WORKAROUND_CVE_2018_3639 must be 1 if DYNAMIC_WORKAROUND_CVE_2018_3639 is 1")